Guess Which One I'm Going to Marry

A young Jewish man excitedly tells his mother he's fallen in love and that he is going to get married. He says, "Just for fun, Ma, I'm going to bring over three women and you try and guess which one I'm going to marry."
The mother agrees.
The next day, he brings three beautiful women into the house and sits them down on the couch and they chat for a while. He then says, "Okay, Ma, guess which one I'm going to marry."She immediately replies, "The one on the right."
"That's amazing, Ma. You're right. How did you know?"
The Jewish mother replies, "I don't like her."